Abrasive blasting of steel structures, such as ships and highway bridges, is a necessary step in maintenance of structures. In particular, abrasive blasting is a precursor to repainting of steel structures. One particular problem encountered with structures such as bridges is that the past painting history of the structure typically will include a lead-based paint. Abrasive blasting tends to liberate lead dust from such structures. Lead dust however, is considered quite toxic and is increasingly regulated. One approach to controlling environmental contamination from the lead dust resulting from abrasive blasting is to recover all of the dust resulting from an abrasive blasting procedure. If the abrasive blasting is accomplished using sand particles, the lead dust ends up mixed with the sand particles. This results in an undesirably high quantity of hazardous waste for subsequent disposal. A more desirable alternative is to employ a reusable steel abrasive particle. Steel is denser than sand and therefore more effectively retains blasting energy.
The most commonly used type of abrasive blasting media currently used is silica sand, fine glass beads, steel shot, steel grit, stainless steel shot, cut wire, grit or similar sized pellets, etc. It is possible to repeatedly use the same abrasive blasting material (or media) several times, if the abrasive blasting material is properly cleaned between each use.
One consequence of the abrasive blasting process on the abrasive blasting materials resulting from high velocity impacting on steel surfaces being cleaned causes them to abrade and generate contaminants such as dirt, paint, mill scale, and rust from the treated surface. At the same time a certain amount of fractured, fine abrasive particles (dust) is also produced.
Various types of devices for cleaning and reclaiming spent abrasive blasting media are available in the related art. Typically, in such a device, the used abrasive blasting media is vacuumed up and carried in an airstream to a cleaning and separating device. Lightweight contaminants are removed by air-washing, while large particulate contaminated material is separated by a separating device.
While known devices for cleaning and reclaiming spent abrasive blasting media have proven to be acceptable for various abrasive blasting media cleaning and reclaiming applications, such devices are nevertheless susceptible to improvements that may enhance their performance, applicability, cost and attractiveness. With this in mind, a need exists to develop a modular approach for arranging different components of the blast skid, recycle skid and vacuum skid as well as other components related to the blasting process.